Blood pressure (BP) medications are remarkably effective in reducing adverse outcomes of uncontrolled hypertension, and optimal adherence reduces heart failure, stroke, and myocardial infarction, and maintains cognitive function. Hypertension is especially prevalent in older adults (~67%), but BP mediation benefits are unrealized for many older adults, as nonadherence is ~50%, leading to decreased quality of life and high health care costs ($290 billion/year in US). We developed the theory-based Multifaceted Prospective Memory Intervention (MPMI), which significantly improved older adults' adherence to BP medications, but benefits did not sustain, once nursing support was removed. We thus developed the Medication Education, Decision Support, Reminding, and Monitoring System (MEDSReM) mobile application (App), which changes medication taking from an effortful process dependent on executive functions and cognitive processes that decline with age, to customized, cue-driven associative processes that are mostly preserved with age. MEDSReM-2 will capitalize on technological advances to integrate additional functionalities to MEDSReM including electronic BP monitoring and provide feedback about the relationship between medication adherence and BP. We will test the efficacy of MEDSReM-2, and expect that the evidence-based and multi-dimensional approach will increase perceived competence and autonomy, resulting in higher and sustained medication adherence and improved BP levels for nonadherent older adults (? 65 years), who self-manage at least one hypertension medication. The aims are: Aim 1: Advance the design of MEDSReM-2, an integrated mobile application that provides education, decision support, reminders, and monitoring to incorporate feedback on adherence related to BP measures. This aim will include implementing and testing new functionalities (e.g., electronic BP monitoring, optical image capture of labels to self-start the App, expanded decision support), as well as user- tested instructional protocols. Aim 2: Determine the efficacy and scalability of MEDSReM-2 through a randomized controlled trial (RCT) to assess efficacy as well as individual patterns of adherence and system use over time. We will screen 448 older people with hypertension to identify 224 nonadherent, randomized to a 6-month intervention study. The primary outcome will be improved adherence (n=112) versus an education control (n=112). Secondary outcomes will be BP, autonomy and competence, and mobile device proficiency. We will examine change in adherence over time in individual participants and moderators of sustainability, and evaluate MEDSReM-2 use patterns to assess factors related to improved adherence and BP management. Successful completion of these aims will result in a theory-based, technology-enhanced comprehensive self- management system that supports hypertension medication adherence and BP management for older adults. MEDReM-2 will foster self-management, through greater personal autonomy and competence, with potential to reduce hypertension-associated risks, save healthcare dollars, and promote independent living of older adults.